Mistral

A strong, cold, usually dry northerly to north-westerly wind channelled from southern France into the Gulf of Lion and western Mediterranean.

It commonly develops when pressure is high to the west or north and lower over the Gulf of Genoa, accelerating air through the Rhône valley and adjacent terrain.

The mistral is a channelled regional wind rather than simply any katabatic flow. It can produce rapid onset, strong gusts, clear air and steep seas extending well offshore.